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Atmospheric Pressure – Learning Activity

 

In this activity, students are asked to create a change in air pressure using a balloon and helium canister, then create an illustration, model or concept map that explains what is happening. Students can also capture the process in “before and after” videos or photos, then share the videos and/or their models on their local community access television broadcast site or  Instagram or Twitter with the hashtag #AirPressureAWAREMission. Soon visit the AWARE Mission Twitter (coming soon) to see experiences and ideas others have posted!

This activity fulfills the CA NGSS standards. This activity explores the science and engineering principles behind the AWARE Mission balloon deployment and air pressure measurements as it relates to height and influences on weather, and includes videos, interactives and media making opportunities. It covers the concepts of air pressure, force, psi, atmospheric pressure, Antarctica, Western Antarctica Ice Sheet (WAIS), altitude and Sonde Balloon deployments by scientists,

Students are required to complete relevant concept chapter readings using Anticipation, Read and Contemplate (reading comprehension) features prior to this activity: Teacher assigns related science passages to air pressure as it relates to force, height and temperature.

Objectives

In this activity, students will work in pairs or groups of 3 or 4 after the initial demo

  1. create a change in pressure that allows them to experience the force of atmospheric pressure (exertion of molecules);
  2. create a balloon model (picture) that explains this phenomenon;
  3. receive comments and questions about their model to co-construct and revise their ideas to help them better understand this phenomenon
  4. view the AWARE Mission Antarctic WAIS Divide Sonde balloon deployment and integrate new information into their model
  5. share their models, pictures and videos on social media.
Materials
  • 4 – 5 easy fill balloon
  • 1 small helium canister with hose attachment provided by teacher
  • scratch paper
  • pencils
  • 2 sticky-note pads (different colors)
  • camera for capturing photos or video (optional)
Activity

Note: Adult supervision strongly suggested.  Safety glasses required by all in the lab.

  1. Define science terms that are on the board:  Helium vs Air, air pressure, psi, atmospheric pressure, force, Antarctica, AWARE Mission, WAIS Divide, altitude, Sonde, Weather Balloon and other relevant terminology.
  2. Show the materials to the class and explain that they will be exploring the concept of pressure in this activity as it relates to Air Pressure measurement in Antarctica.
  3. Initial demo by teacher or Ask for two volunteers: one volunteer will operate the helium tank the other will fill the balloon to bursting
  4. Student pair or groups: Instruct the volunteer to hold the hose of the helium tank into opening of balloon, pointed away from their body,
  5. Count down from 5 and the one volunteer turns on the helium tank.
  6. Observe the expansion and rise process of the balloon.
    • Quick Tip: if the balloon does not fill, check the closure of the helium hose around the neck/opening of the balloon
    • The volunteer directing the helium hose ties off the end of the balloon before it bursts
  7. Once students have experienced or observed the balloon fill and rise process (and maybe burst), have them spend five minutes drawing a conceptual model that explains what they observed.
    • Students should draw two pictures: the first should depict what’s happening before the helium gets turned on, and the second should show what’s happening after the helium is on and the balloon fills and rises.
    • Encourage students to include labels, arrows or anything else that helps them illustrate what they observed.
    • Students should then watch the AWARE Mission Sonde Balloon launch (also students read the caption in the drop-down menu under this YouTube video) and add to their illustration and model/discussion.
  8. Students partner up to discuss their conceptual models of how air pressure is functioning. Students should ask questions about their partner’s model and have a chance to respond to their partner’s questions. After discussing, give students time to revise their models and incorporate any new ideas that came from the discussion.
  9. After revising their models this first time, instruct students to display their drawings on their desks for a gallery walk. The purpose of the gallery walk is for the whole class to see all of the models, ask questions and provide feedback. To do this, distribute two colors of sticky notes:
    • Color 1 = questions or clarifications about the model
    • Color 2 = positive comments or agreement about the model
  10. Students should circulate through the classroom and comment on the models using the colored sticky notes.
  11. Have students return to their seats and read their notes. Give students a final chance to revise their models based on their peers’ comments or questions.
  12. Conclude the activity by leading a class discussion to explain the science of the AWARE Mission Sonde Balloon launch and air pressure. To do this, you can draw a scientifically accurate model on the board. This is also the chance to address any misconceptions about what’s causing the balloon rise. Some other guiding questions for the whole class discussion might include the following:
    • Using a similar setup, what other ideas for experiments do students have?
    • How is this activity related to the pressure change where wind (another force) is involved?
Background for Educators

What is force? Answer through assigned chapter readings.

What is air pressure? Although we don’t usually notice air pressure, the molecules that make up the surrounding air are constantly colliding with us from all different directions. Air pressure is the force of these collisions per unit area. Helium, although lighter than air has what kinds of effects on force and air pressure?  In fact, we often measure pressure in pounds per square inch (psi). This activity helps students understand pressure and changes in pressure by experiencing air pressure in a new way.

What causes a balloon to inflate and rise when helium is turned on? In this activity, participants filled balloons and watched them rise in the room. Before the helium is turned on, there is an equal density of air molecules inside and outside the bag. As described above, the air molecules are colliding with the inside and outside of the bag with equal force per unit area.

When the balloon is filled with helium what happens to the air inside the balloon and its relation to the air outside in terms of pressure?  Most of the room air is replace with helium that has different force and pressure effects on the balloon.  The air pressure inside the balloon is how different from the outside air pressure?  What does this difference cause? Discuss pressure equilibrium. The force of the air molecules colliding with the inside of the bag and the air molecules colliding.  Do they have the same force per unit area outside the balloon as before. The air pressure that is outside of the bag (atmospheric pressure is about how many psi on the surface of the earth).

How is this related to the pressure change in a shrink wrap process?  Create an opposing atmospheric model.

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